Search

The European Fireball Network (EN) has been continuously operating since the late 60s, recording on average 30-40 fireballs every year. The overall objective of this work is to provide the data on these events recorded by the first generation camera stations of the EN to the European Space Agency (ESA) on a regularly basis. The collected metadata of all fireball events will be updated to meet the required import format and will be ingested into the Fireball Information System (FIS), managed by ESA. This also includes the delivery of the corresponding image data. Furthermore, a fast reporting service on fireball events is currently used to the digital all-sky camera located at German Aerospace Center (DLR) in Berlin-Adlershof. Plans to extend the network by installing new digital camera stations are currently under investigation. At least one additional automated camera system is planned to be installed in the vicinity of the first camera station for simultaneous observations of events, allowing the reduction of double-station fireball image data. Information about recorded and confirmed fireball events will be sent to ESA via e-mail in predefined format.

On September 21, 2017, a large fireball appeared over the Netherlands and vanished over the North Sea. Scores of eyewitness reports with descriptions of the phenomenon arrived through our notification e-mail address feuerkugel@dlr.de. By studying these reports, given with varying level of details, and by comparing them with other trusted sources we may appreciate how reliable and complete the reported data are. This might be helpful for us to improve our notification system in the future. Also, reports sometimes include information not easily obtained by other observing techniques. On the other hand, the reporting system is useful to promote public awareness of Earth in the environment of space.

On September 12, 2019 at 12:49:48 (UT) a bolide was observed by hundreds of eye-witnesses from the Netherlands, Germany, Belgium, Denmark and the UK. One day later a small meteorite stone was found by accident in Flensburg. The presence of short-lived cosmogenic radionuclides with half-lives as short as 16 days proves the recent exposure of the found object to cosmic rays in space linking it clearly to the bolide event. An exceptionally short exposure time of ∼5000 years was determined. The 24.5 g stone has a fresh black fusion crust, a low density of, Geochimica et Cosmochimica Acta, 293, ISSN:0016-7037, ISSN:1872-9533

On July 10, 2018 at 21:29 UT extended areas of South-Western Germany were illuminated by a very bright bolide. This fireball was recorded by instruments of the European Fireball Network (EN). The records enabled complex and precise description of this event including the prediction of the impact area. So far six meteorites totaling about 1.23 kg have been found in the predicted location for a given mass during dedicated searches. The first piece of about 12 g was recovered on July 24 close to the village of Renchen (Baden-Württemberg) followed by the largest fragment of 955 g on July 31 about five km north-west of Renchen. Renchen is a moderately-shocked (S4) breccia consisting of abundant highly recrystallized rock fragments as well as impact melt rock clasts. The texture, the large grain size of plagioclase, and the homogeneous compositions of olivine (∼Fa26) and pyroxene (∼Fs22) clearly indicate that Renchen is composed of metamorphosed rock fragments (L5–6). An L-group (and ordinary chondrite) heritage is consistent with the data on the model abundance of metal, the density, the magnetic susceptibility as well as on O-, Ti-, and Cr-isotope characteristics. Renchen does not contain solar wind implanted noble gases and is a fragmental breccia. An unusually large mm-sized merrillite-apatite aggregate shows trace element characteristics like other phosphates from ordinary chondrites. Data on the bulk chemistry, IR-spectroscopy, cosmogenic nuclides, and organic components also indicate similarities to other metamorphosed L chondrites. Noble gas studies reveal that the meteorite has a cosmic ray exposure (CRE) age of 42 Ma and that most of the cosmogenic gases were produced in a meteoroid with a radius of at max. 20 cm based on the radionuclide 26Al and 10–150 cm based on cosmogenic 22Ne/21Ne. K-Ar and U/Th-He gas retention ages are both in the range ∼3.0–3.2 Ga. Both systems do not show evidence for a complete reset 470 Ma ago, and may instead have recorded the same resetting event 3.0 Ga ago., Geochemistry, 79 (4)

In the last 7 years, three meteorites (Blaubeuren, Cloppenburg, and Machtenstein) found in Germany were identified as chondrites. Two of these rocks had been recovered from the impact sites decades ago but were not considered to be meteorites. The aim of this study is to fully characterize these three meteorites. Based on the compositional data on the silicates, namely olivine and low‐Ca pyroxene, these meteorites fit nicely within the H‐group ordinary chondrites. The brecciated texture of Blaubeuren and Cloppenburg (both H4‐5) is perfectly visible, whereas that of Machtenstein, officially classified as an H5 chondrite, is less obvious but was detected and described in this study. Considering chondrites in general, brecciated rocks are very common rather than an exception. The bulk rock degree of shock is S2 for Blaubeuren and Machtenstein and S3 for Cloppenburg. All samples show significant features of weathering. They have lost their original fusion crust and more than half (W3) or about half (W2‐3) of their original metal abundances. The oxygen isotope compositions of the three chondrites are consistent with those of other H chondrites; however, the Cloppenburg values are heavily disturbed and influenced by terrestrial weathering. This is supported by the occurrence of the very rare hydrated iron phosphate mineral vivianite (Fe2+Fe2+2[PO4]2·8H2O), which indicates that the chondrite was weathered in a very wet environment. The terrestrial ages of Blaubeuren (~9.2 ka), Cloppenburg (~5.4 ka), and Machtenstein (~1.8 ka) show that these chondrites are very similar in their degree of alteration and terrestrial age compared to meteorite finds from relatively wet terrestrial environments. They still contain abundant metal, although, as noted, the oxygen isotope data indicate substantial weathering of Cloppenburg. The bulk compositions of the three meteorites are typical for H chondrites, although terrestrial alteration has slightly modified the concentrations, leading in general to a loss of Fe, Co, and Ni due to preferential alteration of metals and sulfides. As exceptions, Co and Ni concentrations in Machtenstein, which has the shortest terrestrial age, are typical for H chondrites. The chemical data show no enrichments in Ba and Sr, as is often observed in different meteorite groups of desert finds., European Regional Development Fund http://dx.doi.org/10.13039/501100008530, Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659